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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').

17104 results found.

  1. GRB050223: No Swift UVOT Detection of Afterglow Emission
  2. GRB050223: ROTSE-III Optical Observations
  3. GRB 050223 Swift/BAT detection of a burst
  4. GRB 050223: Swift XRT Position
  5. GRB050219b: CORRECTION to time of UVOT observations
  6. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  7. GRB 050219b: CORRECTION to refined XRT position
  8. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  9. GRB 050219b: Refined XRT position
  10. GRB 050219b: Swift-BAT detection of a burst
  11. GRB 050219b: CORRECTION: Swift XRT Position
  12. GRB 050219b: Swift XRT Position
  13. GRB 050219a, optical observations
  14. GRB 050219a: Refined XRT position
  15. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  16. GRB 050219: Swift-BAT detection of a burst
  17. GRB050215b: Swift UVOT Detection of Afterglow Emission
  18. GRB 050219: Prompt X-ray position
  19. GRB 050215b: XRT confirmation of IR afterglow candidate
  20. GRB050215b: P60 Optical Observations
  21. GRB 050215b: Swift XRT Source Variability
  22. GRB 050215B: candidate afterglow
  23. GRB 050215b : Lulin follow-up observation
  24. GRB 050215b, BOOTES-2 simultaneous optical observations
  25. GRB 050215B: UKIRT K-band imaging
  26. GRB 050215b: Swift XRT Observations
  27. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  28. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  29. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  30. GRB050215B: ROTSE-III optical observations
  31. GRB050215A: ROTSE-III Optical Observations
  32. short/hard GRB 050202, optical observations
  33. GRB 050128: Radio observations
  34. Further analysis of the short Swift-BAT GRB 050202
  35. GRB 050202: Second epoch radio observations
  36. GRB050202: Radio Observations
  37. GRB 050202: Short burst detected by Swift-BAT
  38. SGR1806-20: Swift-BAT detection of a large normal burst
  39. GRB050128: Faulkes Telescope South observations
  40. GRB050128,optical observations
  41. GRB050126: Updated Swift XRT Position
  42. GRB 050126: Radio Observations
  43. GRB050128 Swift-BAT observations
  44. GRB 050128: Swift XRT prompt afterglow position
  45. GRB 050124: K-band afterglow observations
  46. GRB050126: MASTER optical limit for KECK OT
  47. GRB050126: Burst Parameters Measured by BAT
  48. GRB050126: MASTER optical observations
  49. GRB 050126: Prompt XRT detection and localization
  50. GRB050124: No Swift UVOT Detection of Afterglow Emission
  51. GRB 050117a: Radio Observations
  52. GRB050124,optical observation
  53. GRB050124: Updated Swift XRT Position and Fluxes
  54. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  55. GRB050124: Refined BAT position, spectral and fluence information
  56. GRB050124: Swift-BAT position of a double-peaked burst
  57. GRB050117a: Radio Observations
  58. GRB050117a: Refined analysis
  59. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  60. GRB050117b: Swift-BAT detection of a weak burst
  61. GRB050117: optical observation
  62. GRB 050117, I-band observations
  63. GRB 050117: Optical observation
  64. GRB050117: Refined XRT position
  65. GRB050117: MASTER optical observations
  66. MASTER:GRB050117 SWIFT
  67. GRB050117: Swift-BAT detection of a long multi-peaked burst
  68. GRB050117: Swift XRT Position
  69. SGR1806-20: Swift-BAT observations of two additional bursts
  70. SGR 1806-20, RHESSI observations of the 041227 giant flare
  71. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  72. GRB 041217: Optical observations
  73. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  74. GRB041228: ROTSE-III Optical Observations
  75. GRB041228: Swift-BAT detection of a burst
  76. GRB041219; RXTE ASM Observations
  77. NIR Observations of GRB 041219
  78. GRB041226: ROTSE-III Optical Observations
  79. GRB041226: Swift-BAT detection of a burst
  80. GRB041223: decay of the afterglow
  81. GRB041224: ROTSE-III Optical Observations
  82. GRB 041223: XRT afterglow spectrum and light curve
  83. GRB 041223 Fluence measured by Swift-BAT
  84. GRB041224: Swift-BAT detection of a soft burst
  85. GRB041223: optical and NIR observations with REM
  86. Swift-BAT Time History of GRB041219
  87. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  88. GRB041223: ROTSE-III Optical Observations
  89. GRB041223: Swift-BAT detection of a bright long burst
  90. GRB041220: Swift-BAT burst
  91. GRB 041219 Optical Observations
  92. GRB041219c: Third Burst in One Day from Swift-BAT
  93. GRB041219b: A Swift-BAT burst
  94. Swift-BAT detection of the bright long burst GRB041219
  95. GRB041217: optical limit 30 min after GRB
  96. GRB041217: Optical Observations
  97. GRB041217: NIR and optical observations with REM
  98. GRB041217: P60 Optical Observations
  99. GRB041217: Infrared Observations
  100. GRB041217: The First GRB Located On-Board Swift

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